Many Kepler Planets Have Distant Companions

Wei Zhu (祝伟)

Canadian Institute for Theoretical Astrophysics

2019 March 6, Kepler & K2 SciCon V

Intrinsic architecture of

inner planetary System

30% of Sun-like stars have Kepler planets.

Each system has on average 3 planets within 1 AU.

Fewer-planet systems are dynamically hotter.

Multi-planet systems are not always coplanar.

No Kepler dichotomy.

Our solar systems fits "well" in this picture.

i,~e \propto k^\alpha

Zhu et al., 2018, ApJ, 860, 101

(see Xie et al. 2016; Van Eylen et al. 2018 for e part)

Orbital eccentricity

HATNet

Kepler

Cold Jupiters

Cold Neptunes

(Data from NASA Exoplanet Archive)

Kepler

planets

(30%)

Go beyond 1 AU

~10% of Sun-like stars have cold giant planets (e.g., Cumming+08, Mayor+11)

Cold Neptunes are common

(e.g., Gould+06, Suzuki+16)

The outer companion dominates the mass and angular momentum budget

Super Earth-cold Jupiter relations

Cold Jupiters

Super Earths

22 from Kepler (triangles) + 39 from RV (squares)

Zhu & Wu, 2018, AJ, 156, 92

(see also Bryan et al. 2019)

Cold Jupiters

Super Earths

P({\rm CJ}|{\rm SE}) \approx 33\% {\rm ~vs.~} P({\rm CJ})=10\%

Zhu & Wu, 2018, AJ, 156, 92

(see also Bryan et al. 2019)

22 from Kepler (triangles) + 39 from RV (squares)

Super Earth-cold Jupiter relations

1/3 of Kepler systems have cold Jupiter companions.
- >50%, if [Fe/H]>0.

Cold Jupiters

Super Earths

P({\rm CJ}|{\rm SE}) \approx 33\% {\rm ~vs.~} P({\rm CJ})=10\%

Zhu & Wu, 2018, AJ, 156, 92

(see also Bryan et al. 2019)

22 from Kepler (triangles) + 39 from RV (squares)

Super Earth-cold Jupiter relations

1/3 of Kepler systems have cold Jupiter companions.
- >50%, if [Fe/H]>0.

Cold Jupiters

Super Earths

P({\rm CJ}|{\rm SE}) \approx 33\% {\rm ~vs.~} P({\rm CJ})=10\%

Zhu & Wu, 2018, AJ, 156, 92

(see also Bryan et al. 2019)

22 from Kepler (triangles) + 39 from RV (squares)

Super Earth-cold Jupiter relations

P({\rm SE}) = 30\%

P({\rm SE}|{\rm CJ}) = \frac{P({\rm SE})}{P({\rm CJ})} P({\rm CJ}|{\rm SE}) \approx 100\%

1/3 of Kepler systems have cold Jupiter companions.
- >50%, if [Fe/H]>0.

Cold Jupiters (almost) always have inner super Earth companions!

(Un)Popularity of Solar system

P({\rm no~SE,~CJ}) = [1-P({\rm SE}|{\rm CJ})] \times P({\rm CJ}) \approx 1\%

Zhu & Wu, 2018, AJ, 156, 92

Solar system has no super Earth (70%).

Solar system has a cold Jupiter (10%).

TESS discovers a super Earth in

pi Mensae system

10 M_{\rm J}\\ 3~{\rm AU}\\ e=0.6

5 M_\oplus\\ 6~{\rm d}

Huang et al., (2018)

(see also Gandolfi et al. 2018)

TESS + Gaia

TESS
- 1000s of close-in small planets (e.g., Sullivan+15)

Gaia
- 1000s of cold giants (Perryman+14)

TESS+Gaia provides ~1000 of multi-planet systems

Zhu & Wu, 2018, AJ, 156, 92

Super Earth & cold Jupiter

show strong correlations

Formation
- They do not compete for building blocks.
- Cold Jupiters require more stringent conditions.

Evolution

Zhu & Wu, 2018, AJ, 156, 92

(see also Zhu, 2019, ApJ, 873, 8)

1/3 of Kepler systems have cold Jupiter companions,

what about the other 2/3?

(see Miranda Herman's talk tomorrow)

HATNet

Keck

Cold Jupiters

(~10%)

Cold Neptunes

Most Kepler-like planetary systems have outer giant planets.

Almost all cold giant planets have inner small planets.

Cold planets play important roles in the formation and evolution of the inner system.

Cold giant planets:

Elephant in the room?

Kepler planets

(30%)

Zhu & Wu (2018)

Herman, Zhu, & Wu (2019)

Back-up slides

Intrinsic Architecture

{\rm inclination~dispersion~of~} \\ k{\rm -planet~system} \propto k^\alpha

Zhu, Petrovich, Wu et al., 2018

Planet-planet mutual inclinations affect the occurrence rate of planetary systems

{\rm \#~of~planetary~systems} = \frac{\rm \#~of~detected~systems}{\rm detectability~of~individual~system}

mutual inclination

Planet-planet mutual inclinations affect the occurrence rate of planetary systems

{\rm \#~of~planetary~systems} = \frac{\rm \#~of~detected~systems}{\rm detectability~of~individual~system}

Fraction of Sun-like stars with planets

>50% (Fressin et al. 2013; Petigura et al. 2013; Winn & Fabrycky 2015)

30% (Zhu, Petrovich, Wu et al. 2018)